Means and method of tubulating lamp bulbs



Jun 2, 1931.

J. 5. VAN HORNE MEANS A'ND'METHOD OF TUBULAIINGQLAMP BULBS Filed Aug. 6, 1925 Patented June 2, 1931 UNITED stares PATENT OFFICE JOI IN S. VAN HORNE, OF FRANKLIN,- OHIO, ASSIGNOB TO VAN HORNE TUBE COMPANY, OI FLIN, OHIO, A CORPORATION OF OHIO S AITD a l?" OD OI TUBULATING LAMP BULBS pertaln more especially to means and methodof tubulating such bulbs with view to facilitating manufacture and minimizing breakage manufactured are provided with an inwar 1y extending tubular glass mount for the filament and element support, which mount is attached by fusing to the bottom or base of the bulb. This mount usually comprises a short glass tube flared at its lower end into conformity with the base of the bulb and has its upper end pinched or compressed while at fusing temperature upon the lead wires, which extend through the tubular mount into the interior of the tube or bulb, and upon such filament and element supportsas may be necessary. It is customary to provide within the tubular mount, a tubulating stem or exhaust tube, which communicates with the interior of the bulb through an opening in the mount for the purpose of exhausting the bulb, and if so desired refilling it with an inert gas. Such exhaust tube or tubular stem is attached interiorly of the hollow mount by fusing. Various methods have been proposed for insuring an open passage throu h such tubulating stem to the interior of t e bulb. One of the usual methods heretofore utilized is to fuse the tubulating stem to the interior of the hollow'mount, and while the point of attachment is still at fufi'ng tempera ture to direct a jet of compressed air through the tubulating stem, thereby blowing a hole thru the wall of the mount from the bore of such tube or stem. Another proposed method is to insert the tubulating stem or Shch radio tubes and lamp bulbs as usually temperature during this operation, the heat softened end of the tube will collapse and close the bore or passage. To prevent such collapse, short lengths of metal tubing forming non-yielding metallic bushings are permanently inserted in the ends of the exhaust tubes or tubulating stems. Such permanent bushings not only reduce the diameter of the bore or capacity of the tubulating stem thereby necessltatng the use of a larger tube, but being unyielding they resist the contraction of the compressed ends of the mount .in cooling, thereby subjecting the mount to undue stresses and strains, which results in excessive breakage.

- In the present invention there is contemplated the use of atubulating stem or exhaust tube incorporated in the press of the mount by. fusing, the bore or assage of which is maintained opened, and the collapse of the tube prevented during the pinching or compression of the mount while in a plast state, by the temporary insertion of a remr able resilient core, capable of.yielding Suficiently to compensate for the contraction of the tube and mount when cooling, and which is capable ofsubsequent removal to afford a maximum opening through the tubulating stem. It has been found in practice that a suitable, convenient and economical form of removable resilient core consists of a helically wound wire, which being inserted in the end of the tubulating stem remains in place during. the fusing operation and compression of the mount about the stem, after which such temporary core or bushing is readily removed by pulling upon theprotruding end of the wirewhereupon the coiled wire insert will elongate or unwind from within the tube, leaving the passage or bore of maximum diameter. While a helically wound wire has been found to be convenient and economical other forms of 'elding, removable bushings or inserts may bl utilized to accomplish the same end, and, therefore, the invention is not limited to the specific form of insert.

The object of the invention is to simplify the means and mode of tubulating incandescent lamp bulbs, radio tubes and the like, whereby the methods of manufacture will be facilitated and improved, and the amount of breakage minimized.

A further object of the invention is to provide means for preventing the collapse of the tubulating stem or exhaust tube during the fusing operation, while insuring a passage or bore of maximum diameter leading through the stem into the bulb.

A further object of the invention is to provide an insert or bushing to prevent the collapse of'the tubulating stein or exhaust tube during the fusing operation, which Will yield sufficiently to compensate for the shrinkage and contraction of the tube and mount during cooling, thereby preventing undue stresses and strains within the mount and tube and minimizing breakage.

A further object of the invention is to provide a removable insert or core, capable of resisting the compression of the mount and tube while in a fused condition, yet capable of being readily and easily removed from the tube after the latter has become hardened and cooled.

With the above primary and other incidental objects in view as will more fully appear in the specification, the invention consists of the features of construction, the parts and combinations thereof, and themode of operation or their equivalents as hereinafter set forth and described in the claims.

Referring to the accompanying drawings, wherein is shown the preferred, but obvious- 1y not necessarily the only forms of embodimeht of the invention, Fig. 1 is'a side elevation 'of a radio tubeor bulb of the tipless type, illustrating the tubulating stem, communieating with the interior of the bulb, through the mount and sealed at its outer end. Fig. 2 is a perspective View of the mount and tubulating stem, attached thereto,illustrating the manner of removing the temporary resilient bushing or insert. Fig. 3 illustrates the manner of assembly of the parts in a tubulating machine, wherein the mount and tube are heated to fusing point and compressed. Fig. 4 is a detail viewof the resilient tempora insert or core. Fig. '5 illustrates a modi ed form of stranded removable inserts or cores. Fig. 6 is a detail perspective view of a further modification thereof.

Like parts are indicated by similar characters of reference throughout the several views.

While reference is made herein to incandescent lamp bulbs, and to radio detector and amplifying tubes, it is to be understood that the invention is .not limited to either specific construction, but includes both, and also any 60 other form of vessel or container, to which an exhaust or filling tube is to be attached by fusing or any similar construction wherein a vent port is to be kept open by use of a removable insert or core, which will prevent 65 .the closing or collapse of such vent port,

while the materialis in a plastic condition. In the accompanying drawings, 1 indicates atypical form of bulb or vessel, which is to be exhausted and if the occasion requires, refilled with an inert as or the like. Projecting inwardly from the ase orbottom of the bulb 1, is the mount or press 2. This mount is formed from a short length of glass tube, which being heated to plastic condition is extended or flared at one end as at 3, to form a closure headfor the bulb or vessel 1. The inner end of the mount is pinched or compressed, while in a soft or plastic condition .to embed therein a series of lead wires 5, necessary for the electrical connection of the elements to beinclosed within the bulb or vessel 1. Before pinching or compressing the softened end of the mount 2 upon the lead wires 5, a tubulating stem or exhaust tube 6 is inserted through the'mount 2, to whichit is at-. tached by being embedded in the compressed terminal 4 of the mount. This operationis performed in the usual tubulating machine upon the head of which the several parts are assembled, as shown in Fig. 3. The mount 2 is supported in inverted position upon the head 70f the tubulating machine, with the tubulating stem or exhaust tube 6, centrally disposed therein,,andthe lead wires 5 arranged in spaced relation extending through I the mount 2 and through the spacing, or locating holes in the head 7 of the tubulating machine. To prevent the collapse of the tubulating stem or exhaust tube 6, when the mountis subjected to compression, an insert or core 8 is deposited in the end of the stem'6. This insert or core may be dropped through the tube 6 from its upper end, in the assembly,

shown in-Fig. 3, and is preferably received in a seat or depression in a head 7 of the tubulating machlne so that in the finished productthe extremity of the insert or core 8 may project beyond the extremity of the tube 6 and of the mount 2.

With the several parts assembled as in Fig. 3, the mount tube 2 which is inverted on the top of the head 7 ofthe tubulating machine is subjected to'a blast jet flame which heats the lower end of the tube 2 forming the mount and 'the'extremity of the tubulating stem 6, to a fusing or plastic condition. At this stage the parts are subjected to a pinching or compression operation, usually performed by automatic means which flattens the ends of the I mount 2 into the press 4, serving to seal the lead wires 5 and tubulating stem 6, thereinto. It is to prevent, the collapse of the tube 6 or material reduction of the bore or passage therethrough during this pressing operation while plastic that the core or insert 8 is provided. Obviously, any core or bushing per- -'manently sealed within the end of the exhaust tube will reduce the capacity of the tube. Moreover, arigid-or unyielding core or insert, W111 resist the shrinkage and contrac- 1 I inal diameter.

tion of the glass mount in cooling, resulting in the more or less breakage and setting up mount. To this end the insert or core is preferably a closelywound wire of helical-formation, forming a tubular bushing similar to the commonly known helical spring. Such helically wound wire core or insert will yield or compres sufliciently to compensate for the shrinkage or contraction of the mount and tube, without subjecting such parts to breaking resistance. After the completion of the mount, the end of the insert may be grasped by a pair of pliers or other suitable'instruments or tools, and by slight pull the core is elongated sufliciently to permit its easy removal from the tube. By subjecting such .inserts or core to pulling strain, the successive turns of the. helically wound wire are stretched into approximately their original straight strand formation, causing the successive turns to unwind within the end of the tube. A removal of the core or insert 8, by elongation, or unwinding it from within the tube, leaves the bore or passagejentirely unobstructed and substantially equal to its orig- While a soft wire wound to helical formation has been found to be quite efiicient and the most convenient and simple form for present manufacturing process, it is to be understood that other material such as fiber might be employed'in similar manner and also that the stranded insert or core might be made by other means than helical windings. For example, there has been illustrated in Fig. 5 a form of insert or core in which the strand is folded to and fro upon itself to parallelism to form a small yielding bundle of longitudinally disposed strand sections, which is insertable with'inthe end of the exhaust tube and removable therefrom after the completion of the mount in the manner before described. That is to say, after the completion of the mount, the end of the folded strand being subjected to pulling tension, the successive sections of the strand will be unfolded and pulled from within the'tube. shown a further adaptation, wherein a flat ribbon-like strand is shown folded to and fro manner as that before described. Whatever the form of core maybe, it will be noted that 'it is non-rigid and readily removable subsequent to the com letion of themount. By

this means, manu acturing-processes of tubulatlng incandescent lamps and IfldlO tubes and if desired, be left embedded In Fig. 6 there'isthe like are greatly facilitated, enabling such operations to be erformed rapidly and economically and with minimum breakage of the product.

While the insert or core may be made from various materials including some non-metallic substances as mentioned, the preferable material has been found to be nickel, or an alloy containing nickel.

Although the core or insert is preferably removed to afford a maximum capacity bore, such insertor core when of tubular form may, in theend of the exhaust tube. I

The term lamp bulb, and the like, as emloyed in the description and claims includes 1ghtning. arrestor vessels, mercury switch vessels and other vessels or containers in" which reduced access openings are to be maintained, and those lamp bulbs, radio tu s and. other vessels wherein the vessel is 010 ed and element'leads and thelike, sealed therein by pinching together the walls of the vessel while plastic, without the use .of a separately formed mount which, when used, in effect comprises a wall for such vessels.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail constructionand arrangement of parts withoutde arting from the principle involved or, sacri cing any of its advantages.

While in order to comply with the statute the invention has been described in language more or less specific as to structural features, it is to. be'understood that the invention is not limited to the specific details shown, but that the means and construction herein disclosed comprises the preferred form of severalmodes of putting the invention into ef; feet and the invention is, therefore, claimed in any of itsforms or modifications within the legitimate and valid scope of the appended claims.

Having thus described my invention, I claim:

1. In a' construction of the character described, a mount, a tubulatin stem fused thereto, and a yielding bushing having a passag: communicating with the passage in said tu he combination with a lamp bulb or the like, and a mount connected therewith, and having lead wires extendin through said mount, a tubulatin stem sea edwithin said mount and a yiel able bushing within carried within said tube to prevent the; collagse thereof during the fusing operation. 2;:

the tube at the region where it is so sealed to prevent the collapsethereof and to maintain communication with the interiorofthe bulb. 3. Thecombination with a lamp'bulb or the like, of a mount carried thereby, a tubula'ting k stem fused tosaid mount, and a yielding insert temporarily disposed in said tubulating stem at the region Where it is fused to said mount to prevent the collapse of-the tubulating stem, and subsequently removed thereby in'- suring maintainance of. communication be-. tween the stem and the interior of the bulb.

4. The Combination with a tubulanmount I for a lamp bulb filament or the like, pinched together at its end and lead wiresextending through such pinched portion of the mount,

of an exhaust tube alsoextending through the mount and fused to said mount at the pinched portion thereof, and a removable coiled wire insert within the exhaust tube at such pinched portion to prevent collapse thereof during manufacture, and maintain an open passage through saidtube.

5. The combination with a lamp bulb or the like, of a tubulating tube fused thereto, and ayielding bushing carried within the tube during the fusing process to prevent collapse of the'tube, and minimize breakage during the fusing operation.

6. The combination with a lamp bulb or the like, of a tubulating tube fused thereto,

and a helically coiled wire bushing carried within the-tube during the fusing operation to prevent collapse of'the tubeand minimize breakage.

7. The combination with a lamp bulb or the like, of a tubulating tube fusedthereto,and a yielding metallic insert carried within the tube during the fusing operation to prevent collapse of the tube and minimize breakage.

8. The combination with a lamp bulb or the like, of a tubulating tube fused thereto, and

I a helically wound Wire bushing carried with- 1 in the tube during the fusing operation to prevent collapse of the tube, said bushing being subsequently removable by unwinding the wire from within the tube."

9. The combination with a lamp bulb or the like, of a tubulating tube fused thereto, and a strand of material bent uponitself to form a'removable insert carried within the tube during the fusing operation to prevent I collapse-of said tube and subsequently re movable therefrom by distention of said bent strand-into elongated formation.

1O. The herein described method of tubulating lamp bulbs and the like consisting ininserting a' removable body in the end of an exhaust tube to prevent collapse of the tube,

' lating lamp bulbs and the like, consisting infusing said tube to a' filament mount, distorting the inserted body to make possible its removal from the tube, attaching the mount to the bulb, exhausting the, bulb through'said tube and sealing the tube.

11. The herein described method of tubu inserting a yielding body in the end of an exhaust tube, to prevent collapse ofthe tube and minimize breakage, fusing-the tube carrying such insert to a filament mount, elongating ford an open passage through the tube, attaching the mount to a bulb, exhausting the bulb through said tube and sealing the tube.

12. The herein described method'of tubulating lamp bulbs and the like, consisting in inserting a helically wound Wire in the end of the yielding body to effect its removal to afa tub to prevent collapse of the tube and minimize breakage during attachment fusing the tube carryingsuch insert to a lament mount, unwinding the mm from the interior of the tube, attaching the mount to a bulb,

exhausting the bulb through said tube, and

sealing the tube.

' 13. The herein described method of tubulatinglamp bulbs and the like, consisting in inserting a stranded body within the end of from the tube to afford an unrestricted air passage therethrough', attaching the mount to a bulb, exhausting the bulb through the tube and sealing the tube.

15. The herein described method of main taining an-open passage through a tubulating tube for lamp bulbs and the like during the process of fusing the tube to a bulb structure,

consisting in inserting a removable core in said tube during the fusing operation and subsequently distorting the form of the core to facilitate its removal and removing the core.

' 16. The herein described method of maintaining an open passage through a tubulating tube for lamp bulbs and the like during the process of fusing the tube to a bulb structure,

consisting in temporarily inserting a resilient core in said tube during the fusmg operation and subsequently removing the core.

"17. The herein described method of'maintaining an open passage through a tubulating tube for lamp bulbs and the like during the process of fusing the tube to abulb structure, consisting in temporarily inserting a core comprlsmg a hellcally wound strand in said tube during the fusing operation and subsequently removing the core.

18. The herein described method of maintaining an open passage through a tubulating tube for lamp bulbs and the like during the process of fusing the tube to a bulb structure, consisting in temporarily inserting a removable core of stranded material in said tube,

during the fusing operation and subsequently removing the core.

19. The herein described method of main: taining an open passage through a tubulating tube for lamp bulbs and the like during the process of fusing the tube to a bulb structure consisting in providing a removable core by forming a repetitious succession'of convolutions in a continuous strand of material inserting such core in. said tube during the fusing operation and subsequently removing the core.

. 20. The herein described method of tubulating lamp bulbs and the like wherein an exhaust tube is integrally united with a portion of the lamp bulb structure, including removably inserting a tubular nickel bushing within the end of the said tube to prevent its collapse during the process of its attachment.

21, The herein described met-bod of tubulating lamp-bulbs and the like, wherein an exhaust tube is integrally united with a portion of the lam bulb structure, including inserting a tubu ar bushing formed from a nickel ,bearing alloy within the end of the said tube to prevent its collapse during the process of its attachment.

22. The herein described method of tubulating lam bulbs and the like, wherein an exhaust tu e is integrally united with a portion of the lam bulb structure, including inserting a core ormed from a nickel bearing metallic wire within the end of the said tube to prevent its collapse during the process of its attachment.

23. The herein described method of tubulating lamp bulbs and the like, wherein an exhaust tube is integrally united with a portion of the lamp bulb structure, including removably inserting a non-rigid core within the end of the said tube to prevent its collapse during the process of its attachment.

24. A filament mount, a tubulating tube afiixed thereto by fusin and resilient means carried within the tu e to prevent co1-, lapse during the fusing operation.

25. The combination with a lamp bulb or the like, and a mount connected therewith, and having lead wires extending through said mount, a tubulatin stem sealed within said mount and a resillent bushing within the tube at the region where it is so sealed to prevent the collapse thereof and to maingailii) communication with the interior of the 26. The herein described method of tubulating lamp bulbs and the like, wherein an exhaust tube is integrally united with a portion of the lam bulb structure, includin inserting a resilient core within the end 0 the said tube to prevent its collapse during the process of its attachment.

27. The method of maintaining an access opening in a vessel, including heatin the vessel to a condition of plasticity, positioning a coiled wire insert core, compressing the wall of the heated vessel thereabout while in a plastic state and subsequently removing the core.

28. The combination with a lamp bulb or the like of a tubulating tube fused thereto and a removable flexible insert carried within the tube to prevent collapse of the tube to insure an open passage therethrough.

29. A fusible iressel, a tubulating tube affixed thereto by fusing, and a resilient insert core located within the tube to prevent colto prevent collapse during the fusing opera tion.

In testimony whereof, I have hereunto set my hand this 28th day of July, A. D. 1925.

Y JOHN S. VAN HORNE. 

